When predicting the world fails

From
Jamie Carnie

Anil Ananthaswamy describes the hypothesis that perception is founded on prediction (9 April, p 42). This is supported by my own experience that brain injury can cause perceptual disturbance in two ways.

It can leave the processing of sensory data intact, but still disrupt the generation of predictive perceptual models. And it can disrupt the confident recall of memories needed to fluently generate these models.

The result of these twin effects is a confusing state in which the processing of incoming sound and light signals functions perfectly but cognition becomes defective at precipitating out perceptions of objects and their states. For example, I remember early in my rehabilitation having to examine domestic switches and controls for an inordinate length of time, despite their being visually fully apparent to me, to determine whether they were “on” or “off”.